The term somatotype was a classification of body type devised by William H. Sheldon. He believed that all humans fit within 3 body types (mesomorph, ectomorph, and endomorph) to a certain degree. He defined particular somatotypes as a series of three numbers; each a rating of 1 through 7. An example of one somatotype is a 1-6-3, i.e. medium build, medium height, and underweight. If you struggle remembering the order of body types, just remember s'mores: marshmallow-chocolate-graham cracker (short and fat-medium build-tall and skinny). What kind of s'more are you?